Mental fatigue and “armchair marathon training”

As I mentioned earlier, I went to a conference called “The Future of Fatigue in Exercise” a few weeks ago. One of the researchers I was most interested in hearing from was Samuele Marcora, now at the University of Kent, who has produced a bunch of interesting results on the role of mental fatigue in physical performance over the past few years. For this week’s Jockology column in the Globe and Mail, I wrote about Marcora’s theories and his latest research:

“Improve your marathon time while sitting at your computer” is the kind of claim you expect from an infomercial or a spam e-mail, not from the keynote speaker at an academic gathering.

“It sounds crazy,” Samuele Marcora admitted during his talk at a conference on fatigue at Charles Sturt University in Australia last month, “but it’s actually not.”

Dr. Marcora, a professor at the University of Kent’s Centre for Sports Studies in Britain, has spent the past few years unravelling the surprising links between tired brains and physical performance. His initial results suggest that what we perceive as physical limits are actually highly dependent on our levels of motivation and mental fatigue – and that we may be able to use this fact to our advantage. [...]

Very interesting, but I’m not clear about something. The AX-CPT website says that it’s an evaluation tool, but it’s being used in the follow-on to evaluate its effectiveness in strengthening the brain to withstand effects of fatigue.

@Andy: Good question. Here’s the relevant passage from Marcora’s paper about the AX-CPT:

“This cognitive task requires sustained attention, working memory, response inhibition, and error monitoring (12), and it has been used previously to induce a state of mental fatigue (68).”

The citation is to this 2006 paper (http://www.ncbi.nlm.nih.gov/pubmed/16730824), in which researchers used 90 minutes of AX-CPT to induce mental fatigue, and then took measurements to confirm that the subjects did indeed display signs of mental fatigue (e.g. reduced levels of inhibition) compared to controls. It makes sense: the VO2max test, for instance, is primarily a tool to measure your physical capabilities — but it’s sure as heck effective at inducing physical fatigue!